U.S. Navy Aircraft History

By Tommy H. Thomason

Saturday, August 20, 2022

North American PBJ-1H Carrier Suitability Evaluation

 In November 1944, the recently commissioned Shangri-La was used to conduct carrier evaluations of three aircraft, a Grumman F7F-1 Tigercat, North American a P-51 Mustang, and a North American PBJ-1H Mitchell. Click here for one report on the trials of the F7F and PBJ: http://steeljawscribe.com/2007/10/05/flightdeck-friday-more-oddities. Click here for my post on the Navy's involvement with the P-51: https://tailspintopics.blogspot.com/2011/06/seahorse.html


The otherwise stock PBJ-1H was modified to have a tail hook, catapult provisions, and main landing gear struts that could be swiveled 90 degrees so that it could be lowered on the deck-edge elevator and rolled sideways into the hangar.

Contrary to the "more-oddities" post, the PBJ did not have an SBD tailhook, per se. It would have been too short and possibly under strength. For some reason, the Mitchell's tail skid was deleted when the hook was added.

Catapult provisions included the standard hooks and hold back attachment:

Although the "more-oddities" post states that it was an additional evaluation of the carrier suitability of a tricycle landing gear airplane, my guess is that it was an improvement on a plan to use PBJs for close air support of landings on the Japanese main islands. The concept was to launch them from an aircraft carrier, à la Doolittle, and have them land back at an airfield for turnaround and to be craned back aboard an aircraft carrier to repeat. For one thing, an evaluation of carrier takeoff and landing suitability did not require a demonstration of the ability to strike a dud below deck.

Sunday, March 27, 2022

Naval Fighters Number 113: Douglas F4D-1/F-6A Skyray by Nicholas M. Williams

 

This is a long needed update of Naval Fighters 13 by the same author published in 1984. "Greatly expanded" doesn't do it justice. Forget page count or number of illustrations: this soft-cover monograph printed on high-quality paper weighs a little over two pounds! If you didn't know already, it clearly demonstrates that Nick is the most knowledgeable F4D subject-matter expert.

He covers the lengthy and somewhat troubled development of the F4D in detail, both words and pictures. For example, much of the the account of its nearly disastrous first flight was new to me as were the difficulties in adapting the F4D inlets designed for the J40 engine to the J57. Both the Douglas development and the unit-by-unit histories of Skyray evaluation and operational usage are accompanied by first-hand pilot descriptions of its performance and flight characteristics, warts and all. There are 13 pages of F4D color photos spanning its entire career from initial flight test to its use by the Navy Test Pilot School as in one student's observation, "an interesting and not particularly dangerous 'horrible example' (of unusual flying qualities)".

The monograph concludes with several color pages of F4D model kits that have been produced since the early 1950s. A section of illustrations from the flight and maintenance manuals and closeup photos of details like the landing gear will also be of interest to modelers.

One relatively new and welocome feature of Steve Ginter's monographs is a Table of Contents. It is actually more of a non-alphabetical index but very helpful in quickly finding a topic of interest in its 257 pages like the Test Pilot School quotation above.

I was somewhat surprised that Nick didn't dwell on one of my favorite airplane hobbyhorses, whether or not the F4D was the Navy's first supersonic (in level flight) fighter. (For my opinion, click HERE.) He does describe Douglas' attempts to so (the proposed top speed was Mach 1.2). There is, of course, no question that it could easily break the sound barrier in a descent when not burdened with external fuel tanks or other stores. I'm all but certain that all anecdotal pilot statements that they had been supersonic had done so in a descent or were looking at an inaccurate Mach meter.

Note: Both Nick and I strongly encourage you to buy his monograph directly from Steve, avoiding the middlemen who would otherwise enjoy a significant proportion of the sale price, not Steve. I don't know if he's still offering it at 20% off of the list price, shipping cost included (probably good for the US only) but you might ask him at 805-404-7156.

Friday, March 25, 2022

Douglas A3D Skywarrrior and B-66 Destroyer Differences

 The U.S. Navy's A3D Skywarrior and USAF B-66 Destroyer are very similar airplanes from the same manufacturer, Douglas, initially with very similar missions, medium-range bomber. They look very much the same to the casual observer in a dim light. Some of the differences were necessary but not obvious: the carrier-based Skywarrior had to have folding wings, an arresting hook, and catapult hooks for starters. In fact, however, it's far easier to list what didn't change between the A3D and the subsequent B-66. For all practical purposes, you could say that the B-66 had the same basic overall shape as the A3D except that is, for the forward fuselage and the inboard wing trailing edge. And possibly the wing tips.

For one thing, they had different engines as evidenced by the different engine nacelles. Douglas was lucky to get in line early for deliveries of the new, USAF-funded P&W J57 when the Navy's Westinghouse J40 disappointed. J57 production was all but oversubscribed when the Air Force ordered the B-66 from Douglas so it was saddled with the Allison J71, which had about the same performance but was somewhat inferior in other respects to the J57, as evidenced by the much shorter list of airplanes powered by it.

This is a graphic depicting the most notable external features of the A3D that differentiate it from the B-66:

This one depicts the most notable features of the B-66 that differentiate it from the A3D:

In addition to those details, the two had different radars, bombing/navigation systems, tail-gun turrets, landing gear, wing incidence, inflight refueling probe locations, etc. 

I plan to create a post on one of my aircraft modeler oriented blogs that illustrate the differences in more detail.



Sunday, March 20, 2022

Flight Deck Uniform Colors

 

The picture above was taken of the flight deck crew aboard Shangri-La, probably in 1955. Note the colorful combinations of jerseys and "helmets". These identified the specific duties of each man, officer and enlisted. The practice reportedly began in the beginning aboard CV-1 Langley. I know for certain that the color assigned to a specific responsibility changed over time.

For example (and I apologize for not knowing who created this illustration), in 1943:

From Introduction to Naval Aviation, dated January 1946:

Note purple is assigned to the "chockmen" although the color here could easily be considered blue:


And the "Fueling service crews" are apparently to wear the standard working uniform blue shirt and only be distinguished by red cloth helmets.

 However, in this 1954 picture of F9F Panthers being refueled, it is being done by men wearing both red shirts and red helmets.

Note that they do not have a large "G" on the back of their jerseys as stated in the 1963 first edition of The Naval Aviation Guide:

Note that the catapult crew are not specifically cited as wearing green and "gasoline crews" are wearing red shirts, not yet purple. In fact, purple isn't listed.

However, by 1970 according to Stars and Stripes, fuel crews were assigned the color purple:

From the 1972 edition of The Naval Aviation Guide:

From the 1985 edition of The Naval Aviation Guide:

And "today" (click HERE for a full size image):

And/or watch a video, HERE.

Another major change to the flight deck uniform at some point (the late 1960s?) was the introduction of plastic helmets (cranials) in place of the cloth ones and the requirement to wear life vests (float coats).

Thursday, March 17, 2022

The Definitive Blue Angels’ History - Volume 1

 


I have been remiss in not publicizing this series before, literally a labor of love by Mat Garretson. Volume One covers the years 1946 to 1955 (Volume Two is in work). It is comprehensive in scope (documents and many, many photos from the Blue Angels archives as well as interviews with former Blues), printed on high quality paper, with the photos, artwork, and illustrations in color if the originals were. It was published in two flavors, a limited number of the Plankowner Edition (hardcover, A3 format) and a Regular Edition (softcover, A4 format). The latter is available at a discount through tomorrow, 18 March 2022.

For additional information and to order, click HERE

Sunday, February 27, 2022

Smokin' Tigers by Michael Grove and Angelo Romano

 

Smokin' Tigers is the latest book from noted U.S. naval aviation historian Angelo Romano, coauthored with Michael Grove. It is available in both soft and hard-bound editions. To see more of Angelo's publications and one way to order them, click this LINK.

Consistent features of Angelo's books are high-quality reproduction of many high-resolution pictures, mostly color; operational histories; aircraft configuration and marking information; color profiles; and technical data. In this case, it begins in the beginning with the formation of Composite Squadron Five (VC-5) in 1948 to add nuclear bomb delivery capability to U.S. Navy aircraft carriers.

Heavy Attack Squadron One (VAH-1)—soon to be christened the Smokin' Tigers (note the mushroom-shaped exhalation of smoke)—was subsequently formed in 1955 to introduce the big Douglas A3D Skywarrior in service for that mission. The squadron's long history and the book concludes with the retirement of the North American RA-5C Vigilante in 1979. In between, the various aircraft types it employed, the deployments the squadron made, and the transition from the nuclear-strike mission to multi-sensor reconnaissance are covered in detail.

Although the book's subtitle includes the word "pictorial", it is much more than a collection of pictures as evidenced by the participation in the book's preparation of R.R. "Boom" Powell, a naval aviator who flew the Vigilante and has written a book about it.

As an alternative to the link above, the soft-bound edition of Smokin' Tigers is also available from Ginter Books.


Tuesday, November 2, 2021

A Brief History of U.S.Navy Jet Speed Brakes

One of the early discoveries of the differences between prop-pulled and jet-propelled airplanes was that the latter benefited a great deal from the availability of speed brakes. When the pilot pulled the throttle to idle on the former, the propeller pitch changed rapidly to maintain rpm and the drag increased significantly; there was no need for speed brakes (there were exceptions: dive bombers needed dive brakes to keep the speed within reason in a near-vertical dive; the Grumman F8F Bearcat had small dive-recovery flaps under the wing to more quickly pull out of high-speed dives). Jet planes slowed down with the throttle reduction but far more gradually.

The speed brake design specification was a reduction from maximum speed to a specific slower speed within a given number of seconds. Avoiding much of a pitch change with extension or retraction and minimal buffet when extended was also desired.

The U.S. Navy's first jet, the McDonnell FD-1 (subsequently FH-1) Phantom had speed brakes similar to the spoilers necessary on gliders to allow for the adjustment of the glide angle on final approach. They both increased drag and to some extent, reduced lift. They extended up and down out of the wing on a parallelogram mechanism.

North American initially fitted its FJ-1 with a similar system.

However, after one side extended and the other didn't during a flight test, causing an uncommanded roll and the pilot some concern, North American substituted speed brakes scabbed onto each side of the aft fuselage.

Note that the actuator is located in a well but the speed brake itself simply closes onto the exterior skin of the fuselage.

Vought didn't initially provide its first jet, the F6U Pirate, with speed brakes.

One was quickly added to each side of the aft fuselage:

Grumman provided two speed brakes on the belly of the F9F Panther fuselage just aft of the nose wheel well. The location was retained through the Cougar; however, the F9F-9/F11F Tiger was designed with three speed brakes, one under the nose and two under the main landing gear wheel wells.

Douglas initially configured its F3D Skyknight with three speed brakes on the aft fuselage, possibly to insure the ability of the all-weather fighter to slow down as quickly as possible behind a bogey being intercepted so as not to overrun it or worse, run into it.

Photo via Paul Bless

However, the lower dive brake was deleted for production.

McDonnell retained the FD/FH wing-mounted speed brakes through the F2H-3/4 Banshees.


 On the F3H Demon, however, the speed brakes were relocated to the more common position, either side of the aft fuselage, probably dictated by the different airflow on a swept wing.

Speed reduction was considered particularly necessary when Vought began testing the F7U-1 Cutlass that was capable of breaking the sound barrier in a dive. The problem was that if its single hydraulic system failed for any reason, the control loads became very heavy, increasing with speed. As a result, in addition to the split speed brakes on the inboard trailing edge of the wing, another pair of speed brakes was added under the engine inlets to slow the Cutlass down as quickly as possible so the pilot could regain control.

The extra pair of speed brakes was unnecessary on the F7U-3 since it had a fail-operate flight control system.

Sometimes the aft fuselage lacked a suitable surface for the location of speed brakes. The Douglas F4D Skyray had four small ones, mounted above and below the fillet inboard of the wing.

McDonnell placed the F4H's speed brakes on the bottom of the wing, sandwiched in between the main landing gear wheel well, the trailing edge flap, and the aft Sparrows:


Sometimes it took the engineers more than one attempt at locating the speed brakes. For example, this was the F8U mock up (note that the cannons are located directly under the forward fuselage);

On second thought, they made it a single panel on the belly aft of the nose wheel well and moved the cannons to the side of the forward fuselage.

While this meant that the F8U couldn't be landed with the speed brake extended, the primary reason for that was to add drag on approach so the engine response from the higher thrust required was quicker. Raising the wing for landing provided more than enough drag for that purpose.

The General Dynamics F-111 speed brake doubled as the forward main landing gear door:

The pilot had to bear in mind the increase in drag while the gear was being retracted.

On the F-14, Grumman located the speed brakes on the upper and lower surface of the aft fuselage between the engine nacelles, a single brake above and two below—also see http://www.anft.net/f-14/f14-detail-speedbrake.htm

On the F-18A/B/C/D, McDonnell provided a single speed brake on the top of the aft fuselage that doubled as a billboard.

The Navy determined that some of its jet attack airplanes needed more (and in one case less) speed brake than originally provided.

The North American FJ-4 was repurposed to be a backup to the Douglas A4D. Among other detail changes for the mission, an extra pair of speed brakes was added under the aft fuselage.

The Navy also decided that the original pair of A-6 speed brakes mounted aft of the engines were inadequate so Grumman added a pair of split panels to the trailing edge of the wing tip.

Ironically, it was subsequently decided after some service use that the fuselage-mounted brakes were a problem and the wing-tip ones were adequate, so the former were deleted in production and made inoperable on existing A-6s.

The Vought A-7, originally dubbed the Attack Crusader, was provided with a somewhat bigger speed brake for its strike mission capability;

Although it did not have the raised wing for added drag on approach and extended even farther down than the F8U's, the low-bypass fan engine was presumably deemed to be responsive enough at approach thrust, not to mention the drag of the multiple pylons on the wing.

The North American A3J Vigilante prototypes were built with an enormous speed brake under the fuselage.

However, the Navy decided to delete it for production. The speed brake function was instead provided by the lateral control system, which consisted of deflectors and spoilers on the wings. Instead of them extending asymmetrically for roll control, they all extended at the same time for speed reduction.

The Douglas A3D Skywarrior was also utilized for "dive" bombing, but what looks like a speed brake in front of the bomb bay was actually a spoiler that extended along with the bomb bay doors to eliminate the recirculation of air inside the bomb bay. Otherwise, the bombs would rattle around in the bomb bay after being released instead of dropping out.

The ultimate in speed brakes, however, is similar to the A3J/RA-5C's in that there is no dedicated speed brake per se, but much more effective. The F-18E/F's fly-by-wire flight control system permits speed control without speed brakes by utilizing the existing flight control surfaces, flaps, and the leading edge extension spoilers to add drag when desired. (Note that the flight control system is also programmed to toe-in both rudders for takeoff and approach for lower nose wheel liftoff speed and improved longitudinal stability respectively.)

The leading edge extension (LEX) spoiler had been added to disrupt the LEX-generated vortex that allows for controlled flight at very high angles of attack. When the pilot adds sufficient forward stick at a high angle of attack, the spoilers extend to disrupt the vortex, which results in a faster nose-down response.